The use of ionic catalysts for olefin polymerization where organometallic transition metal cations are stabilized in an active polymerization state by compatible, non-coordinating anions is a well-recognized field in the chemical arts. Typically such organometallic transition metal cations are the chemical derivatives of organometallic transition metal compounds having both ancillary ligands which help stabilize the compound in an active electropositive state and labile ligands at least one of which can be abstracted to render the compound cationic and at least one of which is suitable for olefin insertion. Since inert supports are used industrially for insertion polymerization processes in both of gas phase polymerization and slurry polymerization, technology for supporting these ionic catalysts is also known.
U.S. Pat. No. 5,427,991 and equivalent WO-A-93/11172 describe the chemical bonding of non-coordinating anionic activators to supports so as to prepare polyanionic activators that when used with the metallocene compounds avoid problems of catalyst desorption experienced when ionic catalysts physically adsorbed on inert supports are utilized in solution or slurry polymerization. The supports are core components of inert monomeric, oligomeric, polymeric or metal oxide supports which have been prepared so as to incorporate chemically bound, non-coordinating anions. The teaching of the preparation of polyanionic activators from hydrocarbyl compounds (FIGS. 1, 5-6) entails a number of reactions. A typical reaction for a polymeric core component is that of a treating with the lithiating agent n-BuLi, or optionally lithiating a polymerizable monomer followed by polymerization of monomers into a polymeric segment, to produce a polymer or cross-linked polymer having pendant hydrocarbyl lithium groups. These are subsequently treated with the bulky Lewis acid trisperfluorophenylboron (B(pfp).sub.3) and subjected to an ion exchange reaction with dimethylanilinium hydrochloride ([DMAH].sup.+ [Cl].sup.-) so as to prepare a polymer surface having covalently linked activator groups of [DMAH].sup.+ [(pfp).sub.3 BP].sup.-, where P is the polymeric core component. WO 96/04319 describes a support method using the Lewis acid, noncoordinating anion precursor (e.g., trisperfluorophenyl boron) covalently bound to silica-containing supports through silanol groups, which as an initially formed activator complex donates hydroxyl group protons for protonation of the Group 4 transition metal compound to catalytically active cations.
In addition to the attachment of anionic complexes to support substrates, patent literature describes the attachment of transition metal ligand groups to polymeric supports, the ligand groups then being reacted with transition metal compounds so as to form organometallic compounds bound through cyclopentadienyl ligands to polymeric supports. Such compounds can then be rendered suitable as olefin polymerization catalysts by the use of activating cocatalyst compounds, e.g., such as alkylalumoxanes and phenylborates. See U.S. Pat. Nos. 4,463,135, 5,610,115 and WO 96/35726. WO 96/35726 in particular notes the use of an acrylate-containing, copolymer support having a surface area of less than about 15 m.sup.2 /g, with examples illustrating 2.1 m.sup.2 /g surface area. These catalysts are taught to be of benefit over metal oxide supports in requiring fewer preparation steps since polar moieties such as adsorbed water and hydroxyl groups are not typically present on the polymeric supports. However, this technology presents problems in that the preparation of the support bound ligands limits ligand selection available for subsequent bonding to the transition metal and gives rise to low reaction product yields and undesirable byproducts, some of which may either interfere or compete with subsequent reactions.
Also the functionalization of polymer resin beads for use with or preparation of heterogeneous catalytic species is known. See, e.g., Frechet, J. M. J., Farrall, M. J., "Functionalization of Crosslinked Polystyrene by Chemical Modification", Chemistry and Properties of Crosslinked Polymers, 59-83 (Academic Press, 1977); and, Sun, L., Shariati, A., Hsu, J. C., Bacon, D. W., Studies in Surface Science and Catalysis 1994, 89, 81, and U.S. Pat. No. 4,246,134, this patent describing polymeric carriers of macroporous copolymers of vinyl and divinyl monomers with specific surface areas of 30 to 700 m.sup.2 /g. and the use of such for vinyl monomer polymerization.
The use of supported or heterogeneous catalysts in gas phase polymerization is important as a means of increasing process efficiencies by assuring that the forming polymeric particles achieve shape and density that improves reactor operability and ease of handling. Ineffective catalyst supports permit the production of polymeric fines and resulting fouling of reactor walls or piping. This appears to be due to a number of possible reasons, including premature support particle fragmentation or catalyst desorption both of which can lead to decrease in the control of polymerization. Polymer particle size and density can be degraded and efficiencies lost. Additionally, ionic catalysts provide significant industrial advantages in reducing the amounts of cocatalyst needed and in often providing safer and cheaper synthesis of those cocatalyst activator compounds. These catalysts however can be highly sensitive to polar impurities and accordingly methods of catalyst synthesis that can reduce the production of potential interfering byproducts are desirable.